thought may be Episyrphus balteatus but markings seem slightly different about 6-8mms
No interactions present.
As these hoverflies are common in so many places and in so much of the world I would think they were well studied. Does anybody know why E.balteatus sometimes has these lighter bands?
Episyrphus is very prone to dark forms and forms with these lighter bands. According to Stubbs and Falk, temperature during pupal develoment does affect the extent of dark markings. Very late and very early specimens are often very dark, as a result.
Whether these silvery bands are related to temperature or are just natural genetic variation, I am not sure, but you see them commonly.
My Flickr photos...
Lat/Lng: 50.9, -3.7
OS grid ref: SS8712